In recent years the spreading of digital cameras has increased. A digital camera has an image sensor that has the ability to record light beams and convert them into electrical signals. Examples for an image sensor are charge coupled devices (CCD) semiconductor detectors or complementary metal oxide semiconductors (CMOS) elements. A processing of the electrical signals allows for a representation of the recorded light beams in a format of electronic data. In case that an image is formed on a light sensitive layer the image may for example be stored in an electronic file. The electronic file may have a standard format so that the electronic file is transferable to a computer and displayable on a monitor using a suitable program.
The digital camera includes a lens that forms an image. An image area is sharply focused on the image sensor in case that the image area can be perceived as sharp in a representation following a processing. A sharp perception depends on the requirements for the representation and is influenced by further properties of the total optical system as for example by the resolution of the image sensor. According to the requirements there is a volume of sharp focus that includes a plane of sharp focus. Objects that are within the volume of sharp focus may be formed in a sharp way on the image sensor by the lens, that is, that the image of the objects is focused sharply on the image sensor. In case that the longitudinal axis of the lens is perpendicular, that is orthogonal, to the image sensor the plane of sharp focus is also perpendicular to the longitudinal axis and therefore parallel to the image sensor. This is the case in most digital cameras. In certain situations a plane of sharp focus that is not perpendicular to the longitudinal axis of the lens may be desirable. Cameras with a tilt lens have a lens that is tiltable and a plane of sharp focus may be obtained that is tilted with regards to the longitudinal axis of the lens. Such tilt lenses are mechanically complex and expensive to manufacture. They are specialty lenses that are offered only in few focal distances. Furthermore, a sharp focusing of a large image area may be difficult due to missing options to control the sharpness and automated adjustments. There are further large format cameras with a movable center piece. The movable center piece allows for a tilting of standard lenses. Such large format cameras are also mechanically very complex, expensive to manufacture, and involved when used. A sharp focusing is possible but complex.